Welding-controller.



E. H. TOWER, 1n. L n. H. VAN NEs.

WELDING CONTROLLER,

APPLICATIN FILED MAR. Il. I9l5.

' Patented Mar. 25,1919.

2 SHEETS-SMIT L- E. B. H. TOWER, 111. 61 R.' H. VAN NEST.

WELDING CONTROLLER.

APPLICATION HLED MAR.11.1915.

Patented M111'. 25, 1919.

t 2 SHEETS-SHEET 2.

., UNITED STATES PATENT oEEioE.

EDWIN B. H. TOWER, JR., OF MILWAUKEE, WISCONSIN` AND RAYMOND H. VAN NEST,

OF CHICAGO, ILLINOIS, ASSIGNORS TO THE CUTLER-HAMMER MFG. CO., F MIL- WAUKEE,-WISCONSIN, A CORPORATION OF WISCONSIN.

WELDING-CONTROLLER.

Specification of Letters Patent.

Patented Har. 25, 1919.

Application filed March 11, 1915. Serial No. 13,608.

yT 0 all whom it may concern Be 1t known that we, EnwiN B. H. T owen,

Jr., and RAYMoXn H. TAN ,Xi:sT,' citizcnsof.

* -l ing`.drawings, forming a part of this specifiassociated with the welding circuit.

cation.

This invent-ion relates to welding controllers. l

A The system of electric welding known as i are welding generally` involves striking an subsequently separating the electrodes to -draw an aic. .In order t0 prevent an ex- 'cessive rush of current when the circuit is firstI completed, a current limiting means is Additional means is provided for subsequently re ulatiiig the current limiting ymeans in orc er to increase the voltage across the arc to produce an arc of sufhcient length and volume for welding purposes.

One of the lobjects of the present invention is to provide an improved Welding controller for automatically regulating the welding current.

Another object is to provide a `simplified controller for automatically regulating the welding current. .,Another object is to provide a welding controller in which the number of controlling devices employed is reduced.

Another object is to provide an instrumentality which will aitwniatically regulate ythe welding current and insure that the welding circuit is always in condition for safe' operation.

Other objects and advantages of the in- 50.vention will `hereinafter appear..-

`aThe accompanying drawings illustrate embodiments of theA ii'ivention,l and iin said drawings;

vjustable.

Figure l is a diagrammatic view of a controller embodying the invention.

Fig. 2 isa diagram ot' a similar controller having different connections.

Fig. 3 is a diagram ot' a. modified form of controller.

Figs. l and 5 illustrate other modified forms.

The controller comprises in general a current limiting means 2 for regulating the currentthrough the welding electrodes 3 and '-l, and an automatic switch 5 responsive tothe. current in the welding circuit for controlling the current' limiting means.

The controller shown in Fig. 1 will first be described. 4

The current limiting means comprises a resistance 2 of any suitable type connected in series with electrodes 3 and 4 across supply mains 7 and 8. The resistance 2 limits the current to a safe value when the welding circuit is completed at the electrodes. The character and amountl of this resistance may be varied to suit the working conditions. If desired, the resistance may be made ad- The automatic switch 5 is provided with a movable member 9 electromagnetically controlled by coils 10 and l1 mounted on an insulating base 5. .The movable member 9 carries a Contact 12 adapted to engage a stationary contact 13. The switch is ot a type whichwill i'emaiii `open when the currentthrough its operating means rises rapidly to and is maintained above a predetermined l value. but which will close when the current decreases to a predetermined value. switch of this type is fully described in la co-pending application of Thomas E. Barnum, Serial No. 6.247 filed February 5, 1915.

The coils 10 and 11 of the switch are connected in series and are accordingly slibjected -to the same electrical conditions. They have difi'erent pull characteristics which are so related that when the energizing current rises rapidly to or is maintained above a predetermined value, the switch is held open by the coil l1 and'when the current decreases to a predetermined value. the switch is closed by coil 10. The switch is normally biasedto open position by gravity. Then the ci' cuit through the switchwindings is broken, the member 9 automatically lVhen the current has .decreased to a predetermined value, the switch 5 closes and a circuit is completed from line 7, through the electrodes, resistancev 2.3, conductor 28, contacts l3`12, switch arm 9, binding post 17, coil 10 and conductor 27 to line 8. The adjustable resistance 24 is thereby removed from the circuit. The starting resistance may be varied in this forni of controller and the limiting resistance 23 is always'in circuit to protect against undue rushes of current whether the switch 5 is open or closed.

Fig. 5 illustrates a modification in which three resistances are used. When the circuit is completed at the electrodes 3 and l,

' current Hows from line 7. throueh the elecresistance 31, conductor 32, contacts 13, 12,

switch arm 9 and conductors l5 and 31 to line 8. A shunt circuit is thereby completed around resistances 24 and 29. Suliicient eurrent flows through the circuit including winding l() to keep the switch closed, the amount of current 'required being small since the switch in its closed position Seals the magnetic circuit of the winding. The resistance 31 acts to limit the current in lase -the resistance of the arc should suddenly' be decreased. The resistances 2l and 29 limit the current at starting. The resistance 29 is a positive limiting resistance to prevent a damaging flow of current in the event that the arm 25 should be adjusted so that none of the resistance 2l is in circuit.

It will thus be seen that a simple welding` controller has been provided which will automatically regulate the welding current and .protect the circuit under all conditions. The current is limited at starting to a safe value and after the arc has been established and its resistance sufficiently increased, the limiting means is removed so that a heavy welding current may flow. At. the same time a limiting means 1s provided which will prevent an undue rush of current it' the resistance of the arc should suddenly be decreased. The controller autonnitically reinserts the limiting resistance when the welding circuit is broken so that the apparatus is always in cbndition forsafe operation. The controller comprises a minimum number ot' parts and is devoid of complicated connections and intricate devices.

It should be understood that the embodiment shown is for purposes of illustration only and that other structures .may be devised which will embody the invention and which are included within the spirit and Scope of the appended claims.

Having thus described our invention,

what we claim as'new and desire to secure by Letters Patent of the United States is: -.1. A Welding vcontroller comprsinv a currentylimiting resistance, and a switch thereforf'liavingl ar pair4 of' windings subjected to the same electrical conditions to include said resistance when the welding current tends to rise above a certain value and to exclude said resistance when the welding current is below' a certain value.

2. A welding controller comprising a welding circuit, a switch having a pair of windings subjected to the same electrical conditions and having different pull characteristics, and a resistance controlled b v said switch to be included lin the circuit when thewelding current tends to rise above a certain Vahle and to be excluded from the circuit when the welding current'falls below a certain value.

3. A welding controller having a switch with two windings in series with the welding current, one winding to close the switch. and the other to open the switch, and current limiting means controlled b v said switch.

44. A welding controller having a switch with two windings under the infiuence of the welding current, one winding tending to close theswitch and the other'tending to open the switch, and current limiting means controlled by said switch.

5. A welding controller having a current limiting resistance for the welding' current; and a switch for controlling the resistance, said switch having a pair of windings under the influence of the welding current, and a. circuit closing member connnon to both said windings inuenced by one of said windings to open the switch and by the other of said windings to close the switch.

'6. A welding controller provided with a resistance to limit the welding. current| and an electromagnetic switch having a closing winding and a holding winding whereby the switch is held in one position under certain yelectrical conditions and moved to another position under other electrical conditionsl to automatically control the resistance. j

7. A welding controller provided with a resistance for limitingthe welding current, an electromagnetic switch having a closing winding and a holding winding responsive directljv to the welding current whereby the switch is heldopen when current in the welding circuit is high and is closed to exchule said resistance when the cm ent decreases to a predetermined value. said switch being ,normally biased to open position whereby the resistance is autonmtically reinserted when the welding circuit 'is broken.

S. A welding controller having a switch. a current limitingr resistance controlled by said switch t'or controlling the welding current. and a pair of windingsl conunon to .said switch and in series with thc welding cnr- 1o 1 upon said switch, one .to closethe switch to rent, lone of .said windings preventing closure of said switch upon'l en; abnormal flow of'welding ,Current and the other ofsaid windings effecting the lclosing of said switch upon the flow vof normal Welding currents.

-' 9. A Weldingcontroller-having a current limiting resistance for the :Welding current,

" fa. switch adapted to include and exclude said resistance, and .a pair of windings in series With'the Weldingcurrent and both acting cludev said resistance'upon the How' of 2mb-j .34 I'iorrnell Welding currents.

10,- 1A Welding controller havinga ptir of electrodes ifbetween which Y an arc may be drawn for the welding operation,y e resist?y 1 ance for controlling thewelding current,` a

switch for including and excluding said re-.s sistnce, and alpair of 'Windmgs common to said swltch and both 1n 'series With one of said electrodes at starting to close said switch after but-not l'before the arc is drawn.

In Witness whereof, We have hereunto subscribed our naines inthe presence of two Witnesses. y l

EDWIN B. H. TOWER, JRL RAYMOND H. VAN NEST.

Witnesses:

LA'URA E. SMITH,v 

